fix: performance.timeOrigin (#26787)

`performance.timeOrigin` was being set from when JS started executing,
but `op_now` measures from an `std::time::Instant` stored in `OpState`,
which is created at a completely different time. This caused
`performance.timeOrigin` to be very incorrect. This PR corrects the
origin and also cleans up some of the timer code.

Compared to `Date.now()`, `performance`'s time origin is now
consistently within 5us (0.005ms) of system time.


![image](https://github.com/user-attachments/assets/0a7be04a-4f6d-4816-bd25-38a2e6136926)

1 files changed, 4 insertions, 2 deletions

diff --git a/ext/web/lib.rs b/ext/web/lib.rs
index 4935af5bd..af0fc2c27 100644
--- a/ext/web/lib.rs
+++ b/ext/web/lib.rs
@@ -52,7 +52,8 @@ pub use crate::message_port::Transferable;
 
 use crate::timers::op_defer;
 use crate::timers::op_now;
-use crate::timers::StartTime;
+use crate::timers::op_time_origin;
+pub use crate::timers::StartTime;
 pub use crate::timers::TimersPermission;
 
 deno_core::extension!(deno_web,
@@ -84,6 +85,7 @@ deno_core::extension!(deno_web,
     compression::op_compression_write,
     compression::op_compression_finish,
     op_now<P>,
+    op_time_origin<P>,
     op_defer,
     stream_resource::op_readable_stream_resource_allocate,
     stream_resource::op_readable_stream_resource_allocate_sized,
@@ -123,7 +125,7 @@ deno_core::extension!(deno_web,
     if let Some(location) = options.maybe_location {
       state.put(Location(location));
     }
-    state.put(StartTime::now());
+    state.put(StartTime::default());
   }
 );